T131. Electrophisiological evolution of retinitis pigmentosa

Abstract

Retinitis pigmentosa (RP) is a group of hereditary retinal dystrophies, with a prevalence of 1/4000 inhabitants. It is an incapacitating entity that initially presents with nocturnal vision affectation and progressive decrease of the peripheral visual field, whose symptoms range from childhood to adulthood. Depending on the moment in which the electrophysiological tests are performed, the findings can be very variable. From early phases, when the symptoms are imperceptible or in healthy carriers, to those with an evolved retinosis that affects the entire retina. Objective: To present the findings of the neurophysiological tests in the different times of the evolution of the disease. Material and Methods: Patients diagnosed with RP derived from our unit, we performed Visual Evoked Potentials Pattern (PEV-P), Ganzfeld Electroretinogram (ERG-G) and Multifocal Electrorretinogram (ERG-MF).The results of the tests are exposed in three stages of the disease: preclinical (P): asymptomatic patients, with nictalopia without clear campimetric affectation and healthy carriers, established peripheral retinopathy (RPE): peripheral vision deficit and evolved retinopathy (RE): visual commitment below the 10th central of the visual field. Our observations in patients in phase P: normal PEV-P, ERG-G with alterations of scotopic responses and ERG-MF with lower response density in peripheral rings. In phase RPE: PEV-P normal or slightly altered, ERG-G practically abolished and ERG-MF with only conservation of responses in central rings. In phase RE: PEV-P altered, ERG-G abolished and ERG-MF with only discrete central response or affected diffusely. Neurophysiological tests are not only determinant in the diagnosis, during the different phases of the disease they contribute to assess their evolution and predict prognosis in patients affected with RP.